MRC National Institute for Medical Research, London

The overall standard of writing was high and thought by some judges to be significantly higher than last year; most entrants made great efforts to develop a logical narrative with a clear focus.

In a competition of this kind, judges sometimes have to choose between entries whose chief merit is the quality of information and others whose chief merit is the style of writing. Essays that had good opening and closing paragraphs that addressed the title were slightly favoured. Also entries that were well presented and properly referenced had a clear advantage.

A few entrants wrote in the style used in science journalism. We like to see this but it can be a risky strategy if the arguments are flawed. Notable ideas included entrants who compared the workings of a cell with a factory; compared the uterus to a day-care nursery; began with a dramatic vision of a Nazi death camp; or visualised a world where genes were deliberately altered in the zygote. Sadly these didn't reach the last three, but we look forward to receiving more next year, and perhaps they will go further!

The manufacture of proteins can be switched on or off in particular cells by means of promoters of mRNA synthesis.

The best entries had striking examples of differentiation (ie globin is made only in reticulocytes and no other cell). They recognised control of mRNA synthesis by transcription factors is the key element. They also recognised other levels of control such as methylation of DNA and compaction of chromosomes (although the winner missed this!).

The winner gave a well-written and logical exposition of this conundrum. He alluded to stem cell research and nuclear transfer in a very appropriate way that indicated he knew that changes in the organisation of the transcriptive machinery were an important element in this approach to biomedical research.

The greatest mystery in the development of multicellular creatures is “how do cells start to differentiate as an embryo emerges from a ball of cells?” One of the finalists did show an appreciation of the problem and another essay that did not make it to the final for other reasons gave a good account of the problem.

Embryo selection after genetic screening may enable prospective parents to avoid a poignant tragedy but could this set a dangerous precedent?

This topic was the most popular but also the most testing challenge for the linguistic powers of the entrants although there were many brave efforts (particularly the runner up).

Ethical issues require great sensitivity in the use of language. Good accounts of the science can be severely undermined by “gauche” phrasing or trite and ugly clichés (ie playing God). Although, this was not important for the essay, nobody should be confident that cures for diseases like Huntingdon’s are going to emerge quickly.

In general the mechanics of PGD were well understood but not that PGD is only relevant to prospective parents who know they are carriers of a genetic disease. The most serious criticism of these entries was that we did not feel they conveyed exactly what was meant by Eugenics. The idea was an essentially non-scientific cult that gripped the imagination of lay people and health authorities in certain countries (parts of the USA, Sweden and Nazi Germany). The thing that is nightmarish about Eugenics is the total lack of respect for civil liberties and the bogus science - recognised as nonsense at the time by the genetics community. These people thought they could recognise what they believed were "bad" genes - such as “feeble-mindedness”, criminality or homosexuality -and set out to eliminate them from the population by sterilisation (or worse) of individuals. We should be absolutely clear that PGD is nothing like that!

Many entrants understood PGD was a humane way of avoiding rare and serious genetic disease and rather more humane than abortion. Many entrants appreciated the issues of “saviour siblings” (or “spare parts babies”) and the use of stem cells from the umbilical cord to “cure” genetic diseases in existing siblings. Not many mentioned that Catholic doctrine (but not Jewish, Muslim or protestant) holds that PGD is morally wrong. The question of whether PGD is a precedent for a more dangerous interference with the genetics of humans has been a literary fantasy since “Brave New World”. Many entries recognised this and some showed a clear appreciation that PGD could only be used for two simple traits at most, so this particular fantasy is unlikely to get far. Many entrants appreciate the high cost of PGD means it will not be widely used. The question of sex selection came up in connection with “balancing families” but oddly only a few saw any dangers in this!

Our knowledge of the significance of DNA has accumulated over many years. Can you think of an experiment that conclusively demonstrates that DNA contains genetic information?

Sadly there were only four entries for this important topic. We hoped entries would convey the importance of the Griffiths/Avery experiment in which the transforming principle was identified, together with the evidence that it was DNA.

After Watson and Crick published their proposed structure for DNA, people could see how it could be the source of genetic information; could explain the known facts about inheritance; could be self-replicating and could encode proteins. Experiments with viruses gave additional evidence. Plasmids with known genetic markers provide another kind of proof for the hypothesis. A really elaborate proof would show a gene encoded by a plasmid (such as β-lactamase) can introduce the protein into a bacterial cell and that a mutated gene would give a proteins containing the predicted change in amino acid sequence. It is also possible to make a protein in vitro using DNA as a template. A DNA template of known sequence should give a predicted amino sequence. It would be possible to detect the product and show it was a faithful translation product of the DNA.

It is important in addressing a title like this to focus on critical information (such as the Griffiths/Avery experiment) and to leave aside material that adds nothing to the central argument. (eg Mendels laws are of unquestionable importance in understanding genetics but they tell us nothing about whether DNA carries genetic information).

Human embryos develop in a better environment than fish embryos but may be affected adversely by the poor nutritional state of the mother, by viruses or by chemicals in the maternal bloodstream.

The answer is that it's pretty good but there are some problems! Mammalian offspring develop in a protected environment with a steady supply of nutrients while fish and frogs develop from eggs laid in water where they may be eaten or destroyed in ways the parents have no control over.

Nobody mentioned the dangers of prematurity and the possibility that a mother might carry to term a baby that has disabilities that may test the fortitude of the parents. Although mammalian reproduction is a huge step forward in reproductive efficiency, difficulties remain. Most entries gave an appropriate selection of relevant facts about nutrition, physical safety, and vulnerability to viruses, immune reactions and poisons.

Some entrants discovered that experiences in utero may have very far reaching effects on health and life expectancy after birth, particularly if the baby is underweight at birth. A number of famous studies have shown that individuals born during famines tend to be undersized as adults, usually have a shorter life expectancy and specific health problems such as coronary heart disease and type 2 diabetes. An adequate supply of amino acids is important to ensure the optimum rate of protein synthesis. A deficit of vitamins is likely to retard growth and may cause genetic damage. Premature babies are incompletely developed and struggle to survive because they still require nutrients that normally come from the mother.

We know that our immune system tends to reject transplanted organs but nobody mentioned the miraculous immunity of the embryo to the mother’s immune system.

When cells fail to respond to insulin, the body is unable to keep blood glucose to optimal levels and type two diabetes ensues. The problem has become widespread both in the developed and developing world as lifestyles have changed.

Entrants found it difficult to focus on the title and particularly the idea of what is a serious public health issue. Many entrants found individual pieces of disturbing evidence of the growing trend (particularly in young people) but did not really convey the magnitude of the problem. One startling statistic suggests that in two decades there may be half a billion victims, predominantly in the developing world.

Many entrants wrote well about how the disease originates in the insensitivity of cells to glucose, its connection with obesity and the reasons why people become overweight. Individuals with a body mass index (weight in kg/height in m²) of more than 27 are at risk, especially if fat is concentrated around the waist but people of Indian origin with a BMI of greater than 23 are more vulnerable. There are three reasons why the disease is a public health issue:

1. Many debilitating consequences of the disease such as kidney disease, eye disease, and amputations caused by nerve damage governments will impose great demands on health care.
2. Governments will need powerful information campaigns targeted at prospective parents to reduce the danger.
3. In the developed world it may become a serious economic problem.

The earliest warning of the advance of the disease was amongst particular pre-industrial communities (the Pima Indians of Arizona, and in South Pacific Islands such as Nauru). Sixty years ago these people were lean and fit and the condition was almost unknown. Changes in diet and a reduction in exercise has precipitated a problem that affects perhaps half of the community. Only a few entrants discovered this. The problem is now replicated in many parts of the world, particularly affecting people who emigrate to the developed world from countries with a low standard of living.

There is now a growing body of evidence that babies who are underweight or overweight are more prone to diabetes because of circumstances established in utero. A genetic element predisposes certain people to type 2 diabetes, which may have been an adaptation to a feast-and-famine existence in former times.